Numerous tests have been carried out in the building industry in order to break away from the traditional construction methods, especially on account of the price of materials and the high cost of specialized labor. For roofings, research has been made to eliminate heavy timber by using light, but strong, covering materials; for walls and partitions, conventional construction by means of piling up materials such as stones, bricks, parpen, etc., is substituted by the use of prefabricated story-high panels.
The problem of making self-supporting panels, with enough heat and acoustical insulation as well as being sufficiently watertight to resist vapors and rain, is not at all easy to solve. They must be very light as well as easy to handle in order to be mounted onto the construction frame.
Self-supporting panels have already been manufactured with a heterogeneous structure made of plaques, formed by elements of processed wood, in molded material, with internal air holes or filled with different thermetically insulating materials. Wall-building material which is not sufficiently hard can easily become damaged during transport to the building site. The assembling of such panels by such different fixing means as nailing, sticking or otherwise, can disarticulate the panels under normal efforts applied to walls and coverings, especially due to the effect of violent wind.
The approximate weight of 20 kgs/m.sup.2 sought after for closed premises corresponds approximately to the minimum upthrust effort foreseen, taking into consideration snow and wind.
The impregnation products which protect against dampness are moreover often useless.
It is an object of this invention to overcome the drawbacks of the prior art and to provide building elements which are not only sufficiently light and strong in order to be easily transported to the building site, but which, once on the spot, are highly resistant to powerful outside effects.
The invention also concerns the manufacture of panels which, thanks to their strength and light weight, as well as their anti-freeze, incorruptible, fire-proof structure, can be used as covering material with well-spaced-out timber purlins without rafters, battens or scantlings.
Another object of this invention is to supply a panel which is highly insulated both thermatically and acoustically.
There is also the possibility of molding and coloring the material during manufacture in order to give it a special aspect, such as imitation baked clay tiles, slate, lauzes, shingle-boards of splintered wood, etc., for the outside or decoration in relief for the inside. Moreover, shafts or pipes may be incorporated during manufacture allowing the passage of electric conduits and different fluids.
The grounds of the invention lay essentially on experience according to which concrete, made up of light aggregate, such as perlites, i.e., siliceous materials in nodules, originally volcanic, can be made stronger than usual, if it is bound by resin and silanes or silanols, which increase considerably the cohesion of the material, and reinforce by chemical bridging elements the binding material and the loads. But, for use in large surfaces of light aggregate concrete, the manufacturing processes must be respected in order to obtain a higher mechanical resistance. One of the following three formulas can be chosen.
1. The light aggregate could be impregnated with water added to the resin and silane about 24 hours before mixing with the rest of the components.
2. The light aggregate could be impregnated, about 24 hours before mixing with the rest of the components, with water and a percentage of resin and silane determined by the type of light aggregate chosen, the rest of the resin and silanes to be added when mixing takes place.
3. The light aggregate could be impregnated, about 24 hours before mixing, with water containing an inhibitory charge (quaternary ammonium kind). In this case, the resin and silanes are added to the components when mixing takes place.
As used herein, silanes=organic silicate whose radical R is compatible with the resin used, and SI free gives SIO--OH in the presence of H.sub.2 O in order to assure the liaison.